directed by Peijun Zhang, with collaborative effort from Hanspeter Winkler (Florida State U). Service Mission: The CryoEM Core will: 1) characterize structural features of HIV and host protein complexes by negative staining to determine their suitability for further structural study; 2) determine the structures of complexes/assemblies deemed suitable; 3) develop methods for single particle cryoEM and cryoET to analyze structural heterogeneity.